#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int a[100] = {0};
	int f=0;
	float avg=0;
	float b = 0;
	scanf("%d", &f);

	int i = 0;
	for ( i = 0; i < f; i++)
	{
		scanf("%d", &a[i]);
		avg += a[i];
	}
	b = avg / f;
	printf("%.2f", b);
	return 0;
}